Fan assembly



G. M LARTY FAN ASSEMBLY May 6, 1947.

Filed Aug. 30, 1944 INVENTOR Gordon McLart BY a A ORNEY of air in thepipe.

Patented May 6, 1947 UNITED STATES PATENT OFFICE Gordon McLarty, BattleCreek, Mich. Application August 30, 1944, Serial No. 551,918

3 Claims. 1

circulating apparatus, and in its specific phases to an apparatusadapted for insertion in a duct for increasing the rate of flow of hotor cold gaseous fluid through same.

Fan and motor assemblies have been proposed for use in hot or cold airpipes of furnaces, but all of such assemblies have consisted of a motorand fan suspended directly in the path of flow Where the assembly isused in a hot air pipe, the heat gradually thickens the oil in the motorbearings and in 'due time decreases the speed and utility of the motor.Movement of air directly over the motor causes dust to be deposited onsame, and this is extenuated where the parts are oily from the bearingoil or the like. This dust is a heat insulator and accordingly, themotor gradually increases in temperature in use and finally clogs up andburns out or steps if allowed to run-too long. The present invention wasdiscovered and developed as a result of recognizing the short comingsand difficulties of the prior art in this fluid circulation field.

Accordingly among the objects of the present invention is the productionof a booster fan assembly which is insertable into a duct or chamberwithout the motor of the assembly being exposed to the direct flow offluid in such duct or chamber.

Another object is to provide a substantially hat shaped housing forinsertion into a duct through the side thereof, such housing containinga motor with fan mounted on the shaft of same, the fan being outside ofthe housing.

Another object is to provide a substantially hat shaped housing forinsertion into a duct through the side thereof, such housing having amotor mounted therein with the shaft of the motor extending through theside of the housing and carrying a fan thereon, such opening through thehousing normally being a little larger than the shaft to allow coolingair to flow over the motor and through the opening into the duct under Isuction effect of the fan.

A further object is to provide a substantially hat shaped housing for afan motor, said housing being insulated to protect,the fan motor fromhot or cold fluid flowing around the outer surface of the housing.

A further object is to provide a booster fan assembly particularlyadapted for. use in hot air 2 and at the same time is readily accessiblefor oiling, cleaning, and inspection.

A further object is to provide a hat shaped housing for a booster fanassembly, wherein said housing acts as a support for a fan motor,protects the motor, and thebrim shaped flange on the housing providesmeans for mounting the whole assembly in a suitable hole in the side ofa duct or chamber.

A still further object is to provide a highly efficient booster fanassembly which is simple in construction, easily made, and readilyinstalled and serviced.

Still further objects and advantages of the present invention willappear as the description proceeds.

To the accomplishment of the foregoing and related ends, the invention,then, consists of the means hereinafter fully described and particularlypointed out in the claims, the annexed drawing and the followingdescription setting forth in detail certain means for carrying out theinvention, such disclosed means illustrating, however, but one ofvarious ways in which the principle of the invention may be used.

In the annexed drawing- Figure 1 shows a plan view of a preferred formSf the present invention as installed in a suitable Figure 2'shows apartially sectioned assembly view as taken along line 22 of Figure 1looking in the direction of the arrows.

Figure 3 shows an end view of the assembly as taken along line 3-3 ofFigure 1 looking in the direction of the arrows.

Referring more particularly to the'drawing,

- the duct l is shown with a preferred form of pipes where the fan motoris in a substantially hat shaped housing and exposed to outside airwhere it is kept cooler and cleaner in operation,

the booster fan assembly 2 mounted in place. A conventional form of thisassembly consists of a substantially hat shaped housing 3 which has anopen ended hollow body member 4 and a flange-like brim member 5. Thisbrim member will normally be curved to fit the contour of the duct, andwhere the duct is rounded as diagrammatically illustrated in thedrawing, the brim member will be likewise rounded. The invention,however, is not limited to use with round ducts and the showing of sameis to be considered as diagrammatic of the various constructions whereinthe present invention may be used.

In order to tightly seal the booster fan assembly in the duct, a. gasket6 of conventional construction suitable to the conditions involved, maybe used under brim member 5 and the whole assembly'held in place bymeans of screws! or the like.

Mounted in body member 4 of the booster fan assembly 2 by means ofsupporting members 8 or the like, is an electric motor 9 which has anelongated shaft on which is mounted a propeller ll outside of bodymember 4. The opening is through body member 4 for shaft in may be of asealed construction, but where the assembly is used in a furnace hot airduct, this opening is preferably somewhat larger than the shaft so thatthe suction created by operation of the motor and fan will draw airthrough the housing where it flows over the motor and through theopening into the duct so as to keep the motor relatively cool. The bodymember 4 is also preferably lined with suitable insulation [2 to furtheraid in protecting the fan motor from the heat of the fluid flowingthrough the duct.

To install the assembly, a hole l3 of suitable size is cut in the sideof duct I so as to allow the protruding propeller and body member 4 ofhousing 3 to pass therethrough. The brim member 5 is also made of asuitable shape and width to adequately seal the opening whenthe assemblyis fastened in place. In preferred construction housing member 4 is madeas small as possible to reduce obstruction to fluid flow through theduct l and may be in the form of a streamlined construction stamping asshown. The electric motor is provided with an electric cord H whichconnects same to a suitable source of electricity so that theelectricity for operating the motor may be turned on and offautomatically or manually as desired. In preferred construction thepropeller M will be mounted for rotation substantially on thelongitudinal axis of the duct l, as diagrammatically illustrated in thedrawing, although the invention is not limited to the mounting of thepropeller in this same exact location.

Where the fluid to be circulated through duct i is hot, the hat shapedhousing 3 is preferably either mounted with its open end up or inclinedsidewise so as to permit the direct rising of any heat passing from theinterior of the duct into the inside of body member 4, as well as heatgenerated due to the operation of the motor. This allows natural coolingof the motor by flow of air from the room over same in addition to theair drawn through the housing and into the duct through the smallopening l5 around motor shaft 10. On the other hand if the fluid flowingthrough duct l is abnormally cold so as to adversely affect the motor,then the housing would preferably be installed with open end downward soas to allow the cold air to flow out of the housing and to allow theheat generated by the motor to be pocketed and thus cause it to operateunder more favorable working conditions. The invention, however, is notlimited to the mounting of the assembly in a duct or chamber in thismanner since may be mounted in various ways meeting the requirements ofthe particular situation involved.

Other modes of applying the principle of my invention may be employedinstead of the one explained, change being made as regards the mechanismherein disclosed, provided the means stated by any of the followingclaims or the equivalent of such stated means be employed.

I therefore particularly point out and distinctly claim as my invention:

1. A circulating fan assembly for insertion in an opening through thewall of a duct or the like,

which consists of a hat shaped housing member which has a streamlinedhollow body member closed at one end and open substantially full size atthe other and an outwardly extending brimlike flange at the open end fsaid housing, said brim-like flange being adapted to coact with andclose the opening through the wall of said duct or the like, an electricmotor, means within said housing member for fastening said electricmotor to the latter and wholly within same, said motor having a shaftextending through the wall of said body member, and a propeller mountedon said shaft outside of said body member, whereby the open end of saidhousing member permits natural circulation of air or the like to saidmotor to heat condition same while permitting said housing to berelatively small and short so as to produce a minimum obstruction to theflow of fluid around said housing member.

2. A booster fan assembly for insertion in an opening through the wallof a duct or the like, which consists of a hat shaped housing memberwhich has a hollow body member closed at one end and open substantiallyfull size at the other and an outwardly extending brim-like flange atsaid open end, said brim-like flange being adapted to coact with andclose the opening through the wall of said duct or the like, an electricmotor, means for mounting said motor wholly within said hollow bodymember and supporting same on the latter with the shaft of said motorextending through the wall of said body member, and a propeller mountedon said shaft outside of said body member.

3. A booster fan assembly for insertion in an opening through the wallof a duct or the like, which consists of a hat shaped housing memberwhich has a hollow body member closed at one end and open substantiallyfull size at the other and a brim-like flange extending outwardtherefrom at said open end, said brim-like flange being adapted to coactwith and close the opening through the wall of said duct or the like, agasket between said brim-like flange and the face of the duct which itoverlies, an electric motor, means for mounting said motor wholly withinsaid hollow body member and supporting same on the latter with the shaftof said motor extending through the side wall of said body member, theopening through said hollow body member for said shaft beingsubstantially larger than said shaft so as to permit limited flow offluid over said motor due to the operation of said propeller, a layer ofheat insulation material for said hollow body member, and a propellermounted on said shaft outside of said body member.

GORDON McLARTY.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS FOREIGN PATENTS Country Date British Mar. 26, 1925German Nov. 28, 1922 French Apr. 11, 1932 Number Number

